氯化镧对不同浓度盐、碱胁迫条件下不同种薄荷抗逆性的影响

Study on the Resistance Effect of LaCl_3 on Different Varieties of Mint under Saline-alkali Stress with Different Concentrations

目的:研究氯化镧(LaCl_3)对不同浓度盐、碱胁迫条件下不同种薄荷抗逆性的影响,为薄荷的种植提供理论和试验依据。方法:将4种薄荷(薄荷、留兰香薄荷、美国薄荷、圆叶薄荷)采用低、中、高浓度(25、50、100 mmol/L)的NaCl盐胁迫和NaHCO_3碱胁迫,测定生长指标(存活率、株高、鲜质量、干质量),筛选具有良好抗逆性的薄荷种;测定镧离子(La^(3+))对各浓度盐、碱胁迫下薄荷的生长指标、渗透调节指标[可溶性糖(SS)、可溶性蛋白(SP)、脯氨酸(Pro)]、抗氧化活性指标[超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)]以及挥发油得率,推断La^(3+)对薄荷抗逆性的影响机制。结果:盐、碱胁迫后,美国薄荷、圆叶薄荷的存活率显著降低,不适合在给定气候条件下生长。对于薄荷、留兰香薄荷,在无人工干预的条件下,低浓度盐、碱胁迫可显著增加其生长指标;在无胁迫条件下,La^(3+)可显著增加薄荷的产量及CAT活性;在盐、碱胁迫条件下,与不喷施La^(3+)组比较,喷施La^(3+)组的薄荷在低、中、高浓度盐胁迫下的SOD、CAT、POD活性,在高浓度碱胁迫下的株高、鲜质量,在中、高浓度碱胁迫下的SOD活性及SS含量,在中浓度碱胁迫下的POD活性等指标均有显著升高。结论:喷施La^(3+)后可显著改善中、高浓度碱化土壤(pH>8.0)下的薄荷生长状况;对盐、碱抗性最好的薄荷种是薄荷(Mentha haplocalyx Briq.)。

OBJECTIVE：To study the resistance effect of LaCl3 on different varieties of mint under saline-alkali stress with different concentrations,and provide theoretical and experimental basis for its planting. METHODS：NaCl saline stress and NaHCO3 alkali stress with low,medium,high concentrations（25,50,100 mmol/L）were conducted for 4 kinds of mint [Mentha haploca-lyx Briq.,Mentha spicata Linn.,Monarda didyma L.,Mentha rotundifolia（Linn.）huds]. Growth indexes（survival rate,plant height,fresh weight and dry weight）were determined,and mint species with good resistance were screened. The effect mechanism of La^（3＋） on growth indexes in saline-alkali stress with different concentrations,osmotic regulation indexes [soluble sugar（SS）,soluble protein（SP）, proline（Pro）], antioxidant activity indexes [superoxide dismutase（SOD）, peroxidase（POD）, catalase（CAT）],the yield of volatile oil,and resistance were determined. RESULTS：After saline-alkali stress,M. didyma and M. rotundifolia had low survival rate,which were not suitable for growth under given climatic conditions. For M. haplocalyx and M. spicata,saline-alkali stress with low concentration can significantly increase the growth indexes under no artificial intervention. La^（3＋） can significantly increase the yield and CAT activity under no stress. Compared with non-spraying La^（3＋） group,the SOD,CAT,POD activities of mint added La^（3＋） under saline stress with low,medium,high concentrations,plant height and fresh weight under alkali stress with high concentration,SOD activity and SS content under alkali stress with medium,high concentrations,and POD activity under alkali stress with medium concentration were significantly increased. CONCLUSIONS：Spraying La^（3＋） can significantly improve the growth of M. haplocalyx and M. spicata under alkalized soil with medium,high concentrations. Mentha haplocalyx Briq. is selected as the mint specy with the best saline-alkali resistance.